1. Field of the Invention
The present embodiments relate to a plasma display panel (PDP), and more particularly, to a PDP that keeps up high brightness and has improved color temperature.
2. Description of the Related Art
A PDP is a flat panel display (FPD) that produces an image using gas discharge and has lately attracted much attention because it can be thinned out and embody a high-quality large screen with a wide angular field.
PDPs includes a first substrate and a second substrate, which are spaced apart from each other opposite each other, partition walls, which serve to define discharge cells in which gas discharge occurs between the first and second substrates, a discharge gas, which is filled in the discharge cells to induce discharge, phosphor layers, which are coated on inner surfaces of the discharge cells, and electrodes between which a voltage is applied. In a PDP, discharge arises in the discharge cells due to a direct-current (DC) or alternating-current (AC) voltage applied between the electrodes, creating ultraviolet rays which excite phosphors of the phosphor layers. Thus, the phosphor layers emit visible rays to create an image.
For a conventional PDP, each of the discharge cells includes a phosphor layer formed of any one of red(R), green(G), or blue(B) phosphors (hereinafter, RGB phosphors). The phosphor layers are obtained by sequentially coating RGB phosphors one after another in serial discharge cells.
Three serial discharge cells (specifically, a discharge cell including an R phosphor layer, a discharge cell including a G phosphor layer, and a discharge cell including a B phosphor layer) interact with one another, thus forming a unit pixel.
A brightness ratio of RGB phosphors is typically known as about 28:62:10, and the color temperature of a peak generated in the unit pixel is about 8,000 K.
Generally, the larger the deviation in brightness ratio among the RGB phosphors becomes, the lower the color temperature becomes.
In this case, color temperature is a term that literally represents how hot or cold the color is. The color temperature is typically adjustable in the range of 6,500 to 9,300 K. Here, K is named after W. Thomas Kelvin (1824-1907) and refers to absolute temperature. As the numerical value of color temperature increases, color becomes brighter, colder, and bluer. Inversely, as the numerical value of color temperature decreases, color becomes warmer and redder. Although color temperature is a matter of individual preference, it is known that most people prefer high color temperature (i.e., blue color).
However, in the conventional PDP, a B phosphor has a much lower brightness ratio than R and G phosphors. Therefore, it is necessary to lower the brightness of the R and G phosphors in order to adjust color temperature to most consumers' preference. As a result, the entire brightness of the PDP is degraded.